There are robotic cleaning vehicles for liquid filled containers that are connected to an electrical power source by a cable. These vehicles often follow tortuous paths of travel in accomplishing their cleaning missions and this results in torsional stress building up in the cables as they twist to accommodate the motion of the vehicles. This torsional stress can be somewhat relieved if segments of the cables rotate with respect to other segments of the same cables. This can be facilitated by inserting swivel joints into the cables. However, such joints need to ensure good electrical contact between the cable segments, isolate the electrical contacts from the liquid in which the vehicles are immersed when in operation and prevent the separation of the cable segments from each other when an axial force is applied to the cable segments. It would also be helpful if the segments of a cable could be readily disconnected from each other at a location between the power source and the vehicle when the vehicle is not in operation. One approach is to effect the electrical connection between the cable segments using a classical stereo jack and socket that has been modified by the placement of an O-ring to isolate the electrical contacts from the immersion liquid. For instance, the socket and the jack can be extended to provide for a groove to accommodate an O-ring in one of them that is distal from the tip of the jack when it is inserted in the socket. Such an arrangement is inadequate to resist the axial forces typically experienced by the cable segments when there is not some other structure to isolate the joint from these axial forces. One such structure is a rigid right angle elbow that encompasses a cable segment but it does not always operate to allow relief of the torsional stress from the movement of the vehicle as efficiently as is desired.